SIGN OF CHANGE: The replacement for the Deutsche Bank building at Ground Zero (above) could host New York University.NY Post photo composite

New York University officials are eyeing lower Manhattan — including a tower at the World Trade Center — as part of their 20-year plan to dramatically expand campus housing, classrooms and other services, The Post has learned.

In a letter to the Port Authority and Lower Manhattan Development Corp., NYU Vice President Lynne Brown has requested a meeting with rebuilding officials to determine which downtown sites are available for campus expansion.

The university is planning to add 6 million square feet of new space, about half of which would be built in the college’s core area in and around Greenwich Village. But Brown said the university can’t meet all of it needs in the historic neighborhood.

“For that reason, we would like to discuss lower Manhattan as part of our exploration of remote sites,” she wrote in a letter dated June 11.

Brown cited community officials who have advocated that NYU move into the World Trade Center’s yet-to-be-built Tower 5, which is slated for the site of the former Deutsche Bank building now being demolished.

Tower 5 is expected to include 1.3 million square feet of space. The PA is looking for a developer willing to build either an office tower or a combination hotel and housing high-rise on the site after it’s cleared by the end of this year, which would fit in with NYU’s plans.

“We’re certainly willing to meet with NYU and pleased that there is so much continuing interest in the site during its building,” said a PA spokesman.

Brown said she wants to meet with LMDC officials to learn about any opportunities available downtown and “to assess whether there is some role that the university can play to help revitalize and diversify the area.”

Under NYU’s expansion plan, the university’s campus would grow by 40 percent over the next two decades.

So far, officials have identified Downtown Brooklyn, a corridor along First Avenue in Manhattan — near NYU’s medical center — and Governors Island as possible sites for growth.

Sources familiar with the university’s plans insist that Tower 5 would not be used to replace a proposed 40-story tower that NYU still wants to build on Bleecker Street, which is the most controversial element of the expansion plan.

Julie Menin, chairperson of downtown’s Community Board 1, said a move by NYU to expand in lower Manhattan would find broad community support.

“I raised this idea a number of weeks ago,” Menin said. “I’m very pleased they are taking this idea seriously.

“I think it makes sense for a whole lot of reasons. Tower 5 is perfect for them.”